From their stronghold in Hive City, the Quintessons ruled Cybertron for one million years, inflicting torturous abuse upon the Cybertronians. But without the Dark Guardians, Hive City was a house of cards.

Fiction

The Transformers cartoon

During the final stages of their plan to besiege Hive City, A3, leader of the Autobot rebellion, was plucked from his timeline to the future, where Cybertron was ruled by the Autobots. The Quintessons hoped that removing A3 and his vital Coda Remote would cripple the rebellion. Beta, A3's second-in-command, decided that they had gone too far already, and with the help of Autobots from the future, decided to launch the attack. However, they could not breach Hive City's walls, and the Dark Guardians were too many. Fortunately, A3 returned to his own time and activated the Coda Remote. Without the Dark Guardians, Hive City's defenses were shattered. And the Autobots then found the Quintesson less intimidating... Forever is a Long Time Coming